Related tdf#37531: Make --cat headless/hidden like --convert-to

...which automatically takes care of the open problem from
08960441558743f222280637985690bb8b41b861 "Related tdf#37531: Handle conversion args
sent over pipe" that --cat terminates the called soffice.

Change-Id: Ief8cdf8c1335749dad1504966d635e0519fe92f7
diff --git a/desktop/source/app/cmdlineargs.cxx b/desktop/source/app/cmdlineargs.cxx
index 8fe5532..344dd4a 100644
--- a/desktop/source/app/cmdlineargs.cxx
+++ b/desktop/source/app/cmdlineargs.cxx
@@ -198,6 +198,7 @@ void CommandLineArgs::ParseCommandLine_Impl( Supplier& supplier )
                m_conversionparams = "txt:Text";
                bOpenEvent = false;
                bConversionEvent = true;
                setHeadless();
            }
            else if ( oArg == "quickstart" )
            {
diff --git a/desktop/source/app/dispatchwatcher.cxx b/desktop/source/app/dispatchwatcher.cxx
index bf7ef593..3bbb191 100644
--- a/desktop/source/app/dispatchwatcher.cxx
+++ b/desktop/source/app/dispatchwatcher.cxx
@@ -209,7 +209,8 @@ bool DispatchWatcher::executeDispatchRequests( const std::vector<DispatchRequest
        if ( aDispatchRequest.aRequestType == REQUEST_PRINT ||
             aDispatchRequest.aRequestType == REQUEST_PRINTTO ||
             aDispatchRequest.aRequestType == REQUEST_BATCHPRINT ||
             aDispatchRequest.aRequestType == REQUEST_CONVERSION)
             aDispatchRequest.aRequestType == REQUEST_CONVERSION ||
             aDispatchRequest.aRequestType == REQUEST_CAT)
            nCount++;

        Sequence < PropertyValue > aArgs( nCount );
@@ -221,7 +222,8 @@ bool DispatchWatcher::executeDispatchRequests( const std::vector<DispatchRequest
        if ( aDispatchRequest.aRequestType == REQUEST_PRINT ||
             aDispatchRequest.aRequestType == REQUEST_PRINTTO ||
             aDispatchRequest.aRequestType == REQUEST_BATCHPRINT ||
             aDispatchRequest.aRequestType == REQUEST_CONVERSION)
             aDispatchRequest.aRequestType == REQUEST_CONVERSION ||
             aDispatchRequest.aRequestType == REQUEST_CAT)
        {
            aArgs[1].Name = "ReadOnly";
            aArgs[2].Name = "OpenNewView";
@@ -257,7 +259,8 @@ bool DispatchWatcher::executeDispatchRequests( const std::vector<DispatchRequest
        if ( aDispatchRequest.aRequestType == REQUEST_PRINT ||
             aDispatchRequest.aRequestType == REQUEST_PRINTTO ||
             aDispatchRequest.aRequestType == REQUEST_BATCHPRINT ||
             aDispatchRequest.aRequestType == REQUEST_CONVERSION)
             aDispatchRequest.aRequestType == REQUEST_CONVERSION ||
             aDispatchRequest.aRequestType == REQUEST_CAT)
        {
            // documents opened for printing are opened readonly because they must be opened as a new document and this
            // document could be open already
diff --git a/desktop/unx/source/args.c b/desktop/unx/source/args.c
index 79f2851..bc4c960 100644
--- a/desktop/unx/source/args.c
+++ b/desktop/unx/source/args.c
@@ -39,6 +39,7 @@ static struct {
    { "quickstart", 1, 0, 0, 0, NULL },
    { "minimized",  1, 0, 0, 0, NULL },
    { "convert-to", 1, 0, 0, 0, NULL },
    { "cat",        1, 0, 0, 0, NULL },

    /* pagein bits */
    { "writer",     0, 0, 0, 0, "pagein-writer"  },